Vitiligo: Overview Vitiligo: This skin disease often forms on both sides of the body as shown here on the knees. Vitiligo (vit-uh-lie-go) causes the skin to lose color. Patches of lighter skin appear. Some people develop a few patches. Others lose much more skin color.
Removing and inspecting spark plugs tell you a lot about how well the engine is running and what may be causing problems. All spark plugs should be removed and checked every 30,000 miles - even if your BMW is low maintenance - you're told to change spark plugs at 100,000 miles. This prevents the plugs from seizing in the block, causing expensive repairs down the road. Always note which plug came from which cylinder.
How often should I replace my spark plugs? A: Unfortunately, there is no single answer to this question. As spark plugs grow older, they lose their sharp edges as material from the center and ground electrodes is slowly eroded away. As the gap between these two points grows, the voltage required to bridge the gap increases proportionately. Even the best ignition systems will be strained to supply enough voltage to completely burn the fuel. It is at this point, when fuel is being left unburned, that the time has come to change spark plugs. Replacing worn out spark plugs with new ones (with sharp new edges) effectively restores the ignition system's efficiency.